Lookeen was developed in 2007[1] as an email search tool replacement for Lookout,[2][3] which left the market when it was purchased by Microsoft.

[4] Lookeen enables users to search for files on their local drives, Microsoft Outlook and Microsoft Exchange Server files, and any connected network drives from standard or virtual desktops.

[5] Lookeen won the About.com Reader's Choice award for Best Outlook Add-In in 2010[6] and 2011,[7] and has been reviewed by PCMagazine,[8] The Atlantic,[9] Inc Magazine,[10] PCWorld,[11] and Ghacks,[12] among others[13][14][15] Lookeen was also one of 29 productivity apps recommended in an article on TechCrunch in September 2015.

[16] Lookeen was also mentioned as a 3rd party search utility by The New York Times in December 2016.

Lookeen uses Microsoft add-in technology to integrate a search bar and ribbon into the Outlook client.